An end-stopped line is one in which the grammatical unit of sense stops precisely at the end of the line. The next line of verse picks up a different thought and the next one after that, and so on.

孤联诗句到了句尾语法和句意,都刚好停止，下一句,又表达一个新的意思，下一句又是，依次类推。

耶鲁公开课 - 弥尔顿课程节选